Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P42574 (caspase-3)
45,978 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In this study, we investigated the role of reduced glutathione (GSH) and nuclear factor-kappaB (NFkappaB) in hypoxia-induced apoptosis. Hypoxia caused p53-dependent apoptosis in murine embryonic fibroblasts transfected with Ras and E1A. N-Acetyl-l-cysteine (NAC) but not other antioxidants, such as the vitamin E analog trolox and epigallocatechin-3-gallate, enhanced hypoxia-induced caspase-3 activation and apoptosis. NAC also enhanced hypoxia-induced apoptosis in two human cancer cell lines, MIA PaCa-2 pancreatic cancer cells and A549 lung carcinoma cells. In murine embryonic fibroblasts, all three antioxidants blocked hypoxia-induced reactive oxygen species formation. NAC did not enhance hypoxia-induced cytochrome c release but did enhance poly-(ADP ribose) polymerase cleavage, indicating that NAC acted at a post-mitochondrial level. NAC-mediated enhancement of apoptosis was mimicked by incubating cells with GSH monoester, which increased intracellular GSH similarly to NAC. Hypoxia promoted degradation of an inhibitor of kappaB(IkappaBalpha), NFkappaB-p65 translocation into the nucleus, NFkappaB binding to DNA, and subsequent transactivation of NFkappaB, which increased X chromosome-linked inhibitor of apoptosis protein levels. NAC failed to block degradation by IkappaBalpha and sequestration of the p65 subunit of NFkappaB to the nucleus. However, NAC did abrogate hypoxia-induced NFkappaB binding to DNA, NFkappaB-dependent gene expression, and induction of X chromosome-linked inhibitor of apoptosis protein. In conclusion, NAC enhanced hypoxic apoptosis by a mechanism apparently involving GSH-dependent suppression of NFkappaB transactivation.
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PMID:N-Acetyl-L-cysteine enhances apoptosis through inhibition of nuclear factor-kappaB in hypoxic murine embryonic fibroblasts. 1537 56

Hypericin is the presumed active moiety within Saint John's wort. Extracts of Saint John's wort are widely used as an effective treatment for depression. Available as "over-the-counter" drugs, they are frequently part of the self-medication of patients undergoing radiation therapy for malignant diseases. In addition to antidepressive properties, hypericin has been shown to be able to induce apoptosis and radiosensitize tumor cells, and to have antiinflammatory and phototoxic skin effects. However, the underlying mechanisms are not clear. In this study, we investigated possible inhibitory effects of hypericin on proteasome function and related pathways. Extracts from U373 human glioma cells were incubated with different concentrations of hypericin. Three proteasome activities were monitored using a fluorogenic peptide assay. Activity of the transcription factor NF-kappaB and protein levels of p65, p50, IkappaBalpha and caspase-3 were investigated by EMSA and Western blotting, respectively. Hypericin caused a dose-dependent and photoactivation-independent inhibition of proteasome function. Hypericin treatment (6.25-50 microM) inhibited NF-kappaB, caused accumulation of phosphorylated IkappaBalpha, decreased p50 protein levels and induced cleavage of p65 protein in U373 cells. These effects were observed in MCF-7 cells only at higher concentrations of hypericin (12.5-50 microM). Additionally, inhibition of NF-kappaB activity in U373 cells by hypericin was prevented by caspase inhibition. Although hypericin clearly inhibits proteasome function, its effect NF-kappaB DNA-binding activity was not exclusively proteasome-dependent. The underlying mechanism might also involve caspase activation, a consequence of proteasome inhibition.
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PMID:Hypericin-an inhibitor of proteasome function. 1567 61

To improve the effectiveness of herpes simplex virus (HSV) thymidine kinase/ganciclovir (HSV-tk/GCV) suicide gene therapy, the replication-defective HSV vector TOIkappaB expressing both HSV-TK and a mutant form of the NF-kappaB inhibitor IkappaBalpha (IkappaBalphaM) was developed. TOIkappaB was constructed by recombining the IkappaBalphaM gene into the U(L)41 locus of a replication-defective lacZ expression vector, TOZ.1. Expression of IkappaBalphaM was confirmed by Western blotting, and the ability of the mutant protein to inhibit NF-kappaB nuclear translocation was examined by electrophoretic mobility shift assay. In human glioblastoma U-87MG cells, the p50/p50 dimer of NF-kappaB was already translocated to the nucleus without receptor-dependent signaling by TNF-alpha. Following infection with TOIkappaB, nuclear translocation of NF-kappaB in U-87MG cells was significantly inhibited and caspase-3 activity increased compared with TOZ.1-infected cells. The cytotoxicity of TOIkappaB for U-87MG cells was investigated by colorimetric MTT assay. At an MOI of 3, TOIkappaB infection killed 85% of the cells compared to 20% killed by TOZ.1 infection. In the presence of GCV, these numbers increased to 95-100% for TOIkappaB and 80-85% for TOZ.1. TOIkappaB neurotoxicity measured on cultured murine neurons was relatively low and similar to that of TOZ.1. The survival of nude mice implanted into the brain with U-87MG tumor cells was markedly prolonged by intratumoral TOIkappaB injection and GCV administration. Survival of TOIkappaB+GCV group was significantly longer (P<.02, Wilcoxon test) than for the control groups (TOZ.1 or TOIkappaB only, PBS or PBS+GCV). These results suggest that IkappaBalphaM expression may be a safe enhancement of replication-defective HSV-based suicide gene therapy in vitro and in vivo.
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PMID:Combination gene therapy for glioblastoma involving herpes simplex virus vector-mediated codelivery of mutant IkappaBalpha and HSV thymidine kinase. 1569 8

Peroxisome proliferator-activated receptor gamma (PPARgamma) is a transcription factor important in fat metabolism and is emerging as an important regulator of immunity and inflammation. We previously demonstrated that normal and malignant B lineage cells express PPARgamma and die by apoptosis after PPARgamma agonist exposure. In this study, we used the WEHI-231 mouse B lymphoma and normal mouse spleen B lymphocytes to elucidate the mechanism of PPARgamma agonist-induced apoptosis, and to determine whether an apoptosis rescue mechanism exists. In WEHI-231 cells, the natural PPARgamma agonist 15-deoxy-Delta(12,14)-PGJ(2) and the synthetic PPARgamma agonist ciglitazone induced activation of caspase 3 and caspase 9, a decrease in mitochondrial membrane potential, and caused cleavage of the caspase substrate poly(ADP-ribose) polymerase. We next tested whether CD40, whose engagement delivers a potent prosurvival signal for B cells, could protect B cells from PPARgamma agonist-induced apoptosis. CD40 engagement with CD40L significantly blunted the ability of PPARgamma agonists to induce apoptosis of B lymphocytes and prevented the inhibition of NF-kappaB mobilization by 15-deoxy-Delta(12,14)-PGJ(2) and ciglitazone. Interestingly, PPARgamma agonists induced an increase in IkappaBalpha and IkappaBbeta protein levels, which was prevented with CD40 engagement. The rescue mechanism induced by CD40 engagement was dependent on NF-kappaB, as an NF-kappaB inhibitor prevented rescue. Apoptosis induction by PPARgamma ligands may be important for immune regulation by killing B lymphocytes as a rapid means to dampen inflammation. Moreover, the ability of PPARgamma agonists to kill malignant B lineage cells has implications for their use as anti-B lymphoma agents.
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PMID:CD40 engagement prevents peroxisome proliferator-activated receptor gamma agonist-induced apoptosis of B lymphocytes and B lymphoma cells by an NF-kappaB-dependent mechanism. 1577 64

A central mediator of a wide host of target genes, the nuclear factor-kappaB (NF-kappaB) family of transcription factors, has emerged as a molecular target in cancer and diseases associated with bone destruction. To evaluate how NF-kappaB signaling in tumor cells regulates processes associated with osteolytic bone tumor burden, we stably infected the bone-seeking MDA-MB-231 breast cancer cell line with a dominant-negative mutant IkappaB that prevents phosphorylation of IkappaBalpha and associated nuclear translocation of NF-kappaB. Blockade of NF-kappaB signaling in MDA-MB-231 cells by the mutant IkappaB decreased in vitro cell proliferation, expression of the proinflammatory, bone-resorbing cytokine interleukin-6, and in vitro bone resorption by tumor/osteoclast cocultures while reciprocally up-regulating production of the proapoptotic enzyme caspase-3. Suppression of NF-kappaB transcription in these breast cancer cells also reduced incidence of in vivo tumor-mediated osteolysis after intratibial injection of tumor cells in female athymic nude mice. Immunohistochemistry showed that the cancerous lesions formed in bone by MDA-MB-231 cells express both interleukin-6 and the p65 subunit of NF-kappaB at the bone-tumor interface. NF-kappaB signaling in breast cancer cells therefore promotes bone tumor burden and tumor-mediated osteolysis through combined control of tumor proliferation, cell survival, and bone resorption. These findings imply that NF-kappaB and its associated genes may be relevant therapeutic targets in osteolytic tumor burden.
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PMID:Nuclear factor-kappaB-dependent mechanisms in breast cancer cells regulate tumor burden and osteolysis in bone. 1583 52

1'-Acetoxychavicol acetate (ACA) is a component of a traditional Asian condiment obtained from the rhizomes of the commonly used ethno-medicinal plant Languas galanga. Here, we show for the first time that ACA dramatically inhibits the cellular growth of human myeloma cells via the inhibition of nuclear factor kappaB (NF-kappaB) activity. In myeloma cells, cultivation with ACA induced G0-G1 phase cell cycle arrest, followed by apoptosis. Treatment with ACA induced caspase 3, 9, and 8 activities, suggesting that ACA-induced apoptosis in myeloma cells mediates both mitochondrial- and Fas-dependent pathways. Furthermore, we showed that ACA significantly inhibits the serine phosphorylation and degradation of IkappaBalpha. ACA rapidly decreased the nuclear expression of NF-kappaB, but increased the accumulation of cytosol NF-kappaB in RPMI8226 cells, indicating that ACA inhibits the translocation of NF-kappaB from the cytosol to the nucleus. To evaluate the effects of ACA in vivo, RPMI8226-transplanted NOD/SCID mice were treated with ACA. Tumor weight significantly decreased in the ACA-treated mice compared with the control mice. In conclusion, ACA has an inhibitory effect on NF-kappaB, and induces the apoptosis of myeloma cells in vitro and in vivo. ACA, therefore, provides a new biologically based therapy for the treatment of multiple myeloma patients as a novel NF-kappaB inhibitor.
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PMID:1'-acetoxychavicol acetate is a novel nuclear factor kappaB inhibitor with significant activity against multiple myeloma in vitro and in vivo. 1589 34

Scopoletin (6-methoxy-7-hydroxycoumarin) is a phenolic coumarin and a member of the phytoalexins. In this study we investigated whether scopoletin caused apoptosis in HL-60 promyelocytic cells and, if so, by what mechanisms. We found that scopoletin induced apoptosis as confirmed by a characteristic ladder pattern of discontinuous DNA fragments in a dose-dependent manner. The signal cascade activated by scopoletin included the heterodimeric redox-sensitive transcription factor NF-kappaB, which exhibited an upregulation of nuclear factor-kappa B (NF-kappaB) translocation to the nucleus by increase of IkappaBalpha degradation. In addition, scopoletin activated caspase-3 as was evidenced by both the proteolytic cleavage of the proenzyme and increased protease activity. Activation of caspase-3 resulted in the cleavage of 116 kDa poly(ADP-ribose) polymerase (PARP) to 85 kDa cleavage product in time-and dose-dependent fashions. Prior treatment of the cells with pyrrolidine dithiocarbamate, a potent inhibitor of NF-kappaB activation, or Ac-DEVD-CHO, a specific caspase-3 inhibitor, prevented scopoletin-induced caspase-3 activation, PARP cleavage, and finally DNA fragmentation. Taken together, these results suggest that scopoletin induces NF-kappaB activation, which, in turn, causes activation of caspase-3, degradation of PARP, and eventually leads to apoptotic cell death in HL-60 cells.
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PMID:Scopoletin induces apoptosis in human promyeloleukemic cells, accompanied by activations of nuclear factor kappaB and caspase-3. 1593 54

NF-kappaB is a nuclear transcription factor involved in the control of fundamental cellular functions including regulation of cell survival. We investigated NF-kappaB activation induced by two opposing modulators of cell viability: IL-1beta and glutamate. We found that IL-1beta activated p50, p65 and c-Rel subunits of NF-kappaB, while glutamate activated only p50 and p65 proteins. Cell stimulation by glutamate, correlated with expression of the pro-apoptotic genes Caspase-3, Caspase-2L and Bax. Conversely, IL-1beta induced the expression of the short anti-apoptotic isoform of Caspase-2. Finally, we analysed the effect of the inhibition of IkappaBalpha degradation on glutamate-induced toxicity by using BAY 11-7082, a selective inhibitor of IkappaBalpha phosphorylation. Our results suggest that BAY 11-7082 preserves neuron viability from the glutamate-mediated injury.
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PMID:Inhibition of IkappaBalpha phosphorylation prevents glutamate-induced NF-kappaB activation and neuronal cell death. 1598 28

Nuclear factor-kappaB (NF-kappaB) is constitutively activated in multiple myeloma cells. Several proteasome inhibitors have been shown to be effective against multiple myeloma and may act by inhibiting degradation of IkappaBalpha. Here, we examined the biological effects of a new type of NF-kappaB inhibitor, dehydroxymethylepoxyquinomicin (DHMEQ), which is reported to directly inhibit the cytoplasm-to-nucleus translocation of NF-kappaB. A multiple myeloma cell line, 12PE, which is defective for IkappaBalpha protein, was utilized to determine if IkappaBalpha is concerned with the action of DHMEQ. Meanwhile, U266 was used as a multiple myeloma cell line with normal IkappaBalpha. A proteasome inhibitor, gliotoxin, which is an inhibitor of degradation of phosphorylated IkappaBalpha, failed to inhibit translocation of NF-kappaB in 12PE. In contrast, DHMEQ equally inhibited translocation of NF-kappaB to the nucleus and induced apoptosis to both multiple myeloma cell lines, suggesting that apoptosis resulting from DHMEQ is IkappaBalpha independent. DHMEQ also induced apoptosis in freshly isolated multiple myeloma cells. After DHMEQ treatment, cleavage of caspase-3 and down-regulation of cyclin D1 were observed in both cell lines. In addition, administration of DHMEQ resulted in a significant reduction in tumor volume in a plasmacytoma mice model compared with control mice. Our results show that DHMEQ could potentially be a new type of molecular target agent for multiple myeloma.
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PMID:Dehydroxymethylepoxyquinomicin, a novel nuclear factor-kappaB inhibitor, induces apoptosis in multiple myeloma cells in an IkappaBalpha-independent manner. 1602 Jun 69

Activation of the transcription factor, nuclear factor-kappaB (NF-kappaB), results in up-regulation of not only antiapoptotic genes but also proapoptotic genes, including death receptor 4 (DR4) and death receptor 5 (DR5). Therefore, NF-kappaB activation either suppresses or promotes apoptosis depending on the type of stimulus or cell context. We showed previously that the synthetic retinoid, 6-[3-(1-adamantyl)-4-hydroxyphenyl]-2-naphthalene carboxylic acid (CD437), effectively induces apoptosis particularly in androgen-independent prostate carcinoma cells. This effect was associated with the ability of CD437 to induce the expression of DR4 and DR5. In the present study, we examined the hypothesis that NF-kappaB activation plays a role in CD437-induced death receptor expression and apoptosis. Treatment of DU145 cells with CD437 resulted in a rapid decrease (> or = 3 hours) of IkappaBalpha, which was accompanied by increased translocation of the NF-kappaB subunit p65 from the cytoplasm to the nucleus and increased NF-kappaB DNA-binding activity (> or = 4 hours). The NF-kappaB inhibitor, helenalin, inhibited CD437-induced IkappaBalpha reduction and p65 nuclear translocation. Accordingly, it also abrogated CD437-induced up-regulation of DR4, activation of caspase-8 and caspase-3, and increased DNA fragmentation. Overexpression of an IkappaBalpha dominant-negative mutant blocked not only CD437-induced p65 nuclear translocation but also DR4 up-regulation, caspase activation, and DNA fragmentation. CD437 was unable to decrease IkappaBalpha protein levels and up-regulate DR4 expression in CD437-resistant DU145 cells. Moreover, knockdown of Fas-associated death domain, caspase-8, and DR4, respectively, suppressed CD437-induced apoptosis. Collectively, these results indicate that CD437 activates NF-kappaB via decreasing IkappaBalpha protein and thereby induces DR4 expression and subsequent apoptosis in DU145 cells.
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PMID:Activation of nuclear factor-kappaB contributes to induction of death receptors and apoptosis by the synthetic retinoid CD437 in DU145 human prostate cancer cells. 1602 38


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